Magnesium requirements: new estimations for men and women by cross-sectional statistical analyses of metabolic magnesium balance data

Magnesium: A Defense Line to Mitigate Inflammation and Oxidative Stress in Adipose Tissue

Magnesium (Mg) is involved in essential cellular and physiological processes. Globally, inadequate consumption of Mg is widespread among populations, especially those who consume processed foods, and its homeostasis is impaired in obese individuals and type 2 diabetes patients. Since Mg deficiency triggers oxidative stress and chronic inflammation, common features of several frequent chronic non-communicable diseases, interest in this mineral is growing in clinical medicine as well as in biomedicine. To date, very little is known about the role of Mg deficiency in adipose tissue. In obesity, the increase in fat tissue leads to changes in the release of cytokines, causing low-grade inflammation and macrophage infiltration. Hypomagnesemia in obesity can potentiate the excessive production of reactive oxygen species, mitochondrial dysfunction, and decreased ATP production. Importantly, Mg plays a role in regulating intracellular calcium concentration and is involved in carbohydrate metabolism and insulin receptor activity. This narrative review aims to consolidate existing knowledge, identify research gaps, and raise awareness of the critical role of Mg in supporting adipose tissue metabolism and preventing oxidative stress.

Dietary inadequacies overestimate the blood deficiencies of magnesium, zinc, and vitamins A, C, E, and D among residents of Sao Paulo

BACKGROUND & AIMS

We aimed to estimate the prevalence of the inadequate intake and status of magnesium, zinc, and vitamins A, C, E, and D and identify factors associated with micronutrient deficiency in serum/plasma among residents of São Paulo, Brazil.

METHODS

Data from 824 individuals aged ≥14 years were obtained from the 2015 ISA-Nutrition, a population-based, cross-sectional survey. Dietary and supplement intakes were assessed using two 24-h dietary recalls, and the micronutrient inadequacies were estimated using the National Cancer Institute method. Micronutrient status was measured in serum or plasma, and deficiency was established according to the lower limit of the reference values. Receiver operating characteristic curve analysis was used to identify the effect of intake on the micronutrient status in serum/plasma. Logistic regression analysis was applied to assess the association between micronutrient status and individual characteristics.

RESULTS

More than 80% of the population had an inadequate dietary intake of magnesium, vitamin E, and vitamin D. Males had a high prevalence of inadequate dietary intake of vitamin A and zinc. A high-to-moderate prevalence of inadequate vitamin C intake was observed. Vitamin D was the only nutrient with a deficient status comparable to its dietary inadequacy. The other nutrients demonstrated a lower deficiency prevalence compared to dietary inadequacy, and vitamin A demonstrated the lowest prevalence of deficiency in plasma. Generally, dietary intake showed a non-notable association with micronutrient deficiency in serum/plasma. Individuals with fasting glucose concentrations ≥100 mg/dL and those using diuretic drugs had a higher risk of serum magnesium deficiency. Those using lipid-lowering drugs and those with high plasma adiponectin concentrations had a higher risk of serum zinc deficiency. Individuals who smoked and those with hypertension showed a higher risk of plasma vitamin C deficiency. Individuals with average leptin concentrations had a higher risk of plasma vitamin E deficiency. Finally, those with sufficient leisure-time physical activity had a lower risk of serum vitamin D deficiency.

CONCLUSIONS

Residents of the urban areas of São Paulo demonstrated substantially inadequate intakes of most of the assessed micronutrients; however, micronutrient deficiency in serum/plasma was not associated with dietary inadequacy, and it usually demonstrated a lower prevalence than dietary indicators. Thus, using micronutrient intake to determine the serum/plasma profile should be done with caution. The status of the micronutrients varied according to individual characteristics, indicating the interplay of complex mechanisms underlying micronutrient balance.

Dietary macrominerals: Updated review of their role and orchestration in human nutrition throughout the life cycle with sex differences

Macrominerals play vital roles in a multitude of physiologic systems. A myriad of biochemical reactions are dependent on or affected by these electrolytes. The current review attempts to identify the role of macrominerals as calcium, phosphorus, magnesium, sodium, potassium and sulfur in human health, in addition to their absorption and homeostasis inside the body. We also focused on their amount in major food sources and the recommended daily intake of each macromineral. In addition, a deep insight into the orchestration of the 6 different macrominerals' requirements is presented across the human life cycle, beginning from fertility and pregnancy, and reaching adulthood and senility, with insight on interactions among them and underlying action mechanisms. The effect of sex is also presented for each mineral at each life stage to highlight the different daily requirements and/ or effects. The current review identified the role of macrominerals in human health, in addition to their absorption and homeostasis in the body. Based on the in-depth understanding of the factors influencing the metabolism of macrominerals, we could better explore their safety and possible therapeutic potential in specific disorders. There is still a need to precisely demonstrate the bioavailability of macrominerals from various types of functional food.

Setting references for daily intake of micronutrients: A study on magnesium

OBJECTIVES

The Institute of Medicine stratifies the references for daily nutrient intake into age and sex groups, considering that the basal metabolic rate varies according to these aspects, and in most cases, it extrapolates the values calculated for adults to children, because their body weights are different. In this context, this study aimed to evaluate the recommendation for magnesium in children according to energy expenditure.

METHODS

This was an observational study using the database of the Social Changes, Asthma and Allergy in Latin America (SCAALA) cohort, which randomly collected information from 1445 children ages 4 to 11 y. Of these, 480 (33%) were part of the present study (children between 7 and 11 y old with eutrophic body mass index and adequate growth). Information on food intake was obtained from the child's parents or legal guardians through a 24-h recall. The population was characterized using static analyses such as the Student t test, Pearson correlation coefficient, and linear regression.

RESULTS

The mean age of the sample was 8.5 ± 0.96 y, and 54% were males. The mean magnesium intake was 149 ± 70 mg, with a high correlation observed between energy expenditure and magnesium intake (boys: R, 0.716; P <0.001; girls: R, 0.641; P < 0.001).

CONCLUSIONS

The metabolic rate can be considered a reference variable for recommending the daily intake of the studied nutrient, aiming to avoid deficiencies and food poisoning because of poor intake.

Divergent effects of sex and calcium/vitamin D supplementation on serum magnesium and markers of bone structure and function during initial military training

Maintaining Mg status may be important for military recruits, a population that experiences high rates of stress fracture during initial military training (IMT). The objectives of this secondary analysis were to (1) compare dietary Mg intake and serum Mg in female and male recruits pre- and post-IMT, (2) determine whether serum Mg was related to parameters of bone health pre-IMT, and (3) whether Ca and vitamin D supplementation (Ca/vitamin D) during IMT modified serum Mg. Females (n 62) and males (n 51) consumed 2000 mg of Ca and 25 μg of vitamin D/d or placebo during IMT (12 weeks). Dietary Mg intakes were estimated using FFQ, serum Mg was assessed and peripheral quantitative computed tomography was performed on the tibia. Dietary Mg intakes for females and males pre-IMT were below the estimated average requirement and did not change with training. Serum Mg increased during IMT in females (0·06 ± 0·08 mmol/l) compared with males (-0·02 ± 0·10 mmol/l; P < 0·001) and in those consuming Ca/vitamin D (0·05 ± 0·09 mmol/l) compared with placebo (0·001 ± 0·11 mmol/l; P = 0·015). In females, serum Mg was associated with total bone mineral content (BMC, β = 0·367, P = 0·004) and robustness (β = 0·393, P = 0·006) at the distal 4 % site, stress-strain index of the polaris axis (β = 0·334, P = 0·009) and robustness (β = 0·420, P = 0·004) at the 14 % diaphyseal site, and BMC (β = 0·309, P = 0·009) and stress-strain index of the polaris axis (β = 0·314, P = 0·006) at the 66 % diaphyseal site pre-IMT. No significant relationships between serum Mg and bone measures were observed in males. Findings suggest that serum Mg may be modulated by Ca/vitamin D intake and may impact tibial bone health during training in female military recruits.

The kidney reabsorption-related Magnesium Depletion Score is associated with increased likelihood of abdominal aortic calcification among US adults

BACKGROUND

Kidney reabsorption has a vital role in magnesium homeostasis. This study aimed to determine the relationship between the kidney reabsorption-related magnesium depletion score (MDS) and abdominal aortic calcification (AAC).

METHODS

We obtained the data of 2640 individuals from the National Health and Nutrition Examination Survey (NHANES) database and analyzed the relationship between MDS and AAC scores. MDS is a scoring system developed to predict status of magnesium deficiency that fully considered the pathophysiological factors influencing the kidneys' reabsorption capability. AAC was quantified by the Kauppila score system based on dual-energy X-ray absorptiometry. We performed stratified analysis and multiple equation regression analysis. R and EmpowerStats were used for data analysis.

RESULTS

A total of 2640 participants were included with the mean AAC score of 1.47 ± 0.07. Participants in higher MDS tended to have higher AAC scores (MDS scored 0: 0.75 (0.56, 0.93), MDS scored 1: 1.02 (0.84, 1.21), MDS scored 2: 2.34 (1.80, 2.87), MDS scored 3: 3.19 (2.46, 3.92), MDS ≥ 4: 4.99 (3.49, 6.49)). Compared with those in the lowest MDS scored 0, the highest subgroup (MDS ≥ 4) was associated with a higher AAC score (β = 4.24, 95% CI: 2.78-5.70, p < 0.001), and the association was not altered (β = 1.81, 95% CI: 0.54-3.09, p = 0.002) after adjusting for numerous covariates. Subgroup analyses showed that stronger associations between MDS and AAC score were detected in adults with lower levels of magnesium intake and older (all p for interaction < 0.05).

CONCLUSIONS

The MDS is a promising tool for identifying individuals with magnesium deficiency status who may benefit from dietary magnesium supplementation to reduce the risks of AAC.

Magnesium Status and Ca/Mg Ratios in a Series of Children and Adolescents with Chronic Diseases

Magnesium (Mg) is an essential divalent cation involved in various enzymatic reactions that regulate vital biological functions. The main goal was to evaluate Mg status and its association with nutritional indicators in 78 children and adolescents with chronic diseases. We assessed anthropometric, biochemical, diet, body composition, and bone densitometry valuations. Serum Mg and Ca levels were determined using the standardized method and diet calcium (Ca) and Mg consumption by a prospective 72 h diet survey. Mean serum Ca (9.9 mg/dL), Mg (2.08 mg/dL) dietary Ca (102% DRI: Dietary Reference Intake), and Mg intake (105% DRI) were normal. A total of 45% had hypomagnesemia, 12% had hypermagnesemia, and 26% and 24% had inadequate and high Mg intake, respectively. Only 6% of patients had poor Mg intake and hypomagnesemia, and 54% and 90% of our series had an elevated serum Ca/Mg ratio > 4.70 (mean 4.79) and a low Ca/Mg intake ratio < 1.70 (mean 1.06), respectively. Both Ca/Mg ratios were linked with the risk of developing other chronic conditions such as cardiovascular disease, type 2 diabetes, syndrome metabolic, and even several cancers. Therefore, 79% of children and adolescents with chronic diseases were at elevated risk of having abnormal Mg status and developing other chronic illnesses.

Beyond Nutrient Deficiency-Opportunities to Improve Nutritional Status and Promote Health Modernizing DRIs and Supplementation Recommendations

The US Dietary Guidelines for Americans (DGA) provide dietary recommendations to meet nutrient needs, promote health, and prevent disease. Despite 40 years of DGA, the prevalence of under-consumed nutrients continues in the US and globally, although dietary supplement use can help to fill shortfalls. Nutrient recommendations are based on Dietary Reference Intakes (DRIs) to meet the nutrient requirements for nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group and many need to be updated using current evidence. There is an opportunity to modernize vitamin and mineral intake recommendations based on biomarker or surrogate endpoint levels needed to 'prevent deficiency' with DRIs based on ranges of biomarker or surrogate endpoints levels that support normal cell/organ/tissue function in healthy individuals, and to establish DRIs for bioactive compounds. We recommend vitamin K and Mg DRIs be updated and DRIs be established for lutein and eicosapentaenoic and docosahexaenoic acid (EPA + DHA). With increasing interest in personalized (or precision) nutrition, we propose greater research investment in validating biomarkers and metabolic health measures and the development and use of inexpensive diagnostic devices. Data generated from such approaches will help elucidate optimal nutrient status, provide objective evaluations of an individual's nutritional status, and serve to provide personalized nutrition guidance.

Magnesium in Aging, Health and Diseases

Several changes of magnesium (Mg) metabolism have been reported with aging, including diminished Mg intake, impaired intestinal Mg absorption and renal Mg wasting. Mild Mg deficits are generally asymptomatic and clinical signs are usually non-specific or absent. Asthenia, sleep disorders, hyperemotionality, and cognitive disorders are common in the elderly with mild Mg deficit, and may be often confused with age-related symptoms. Chronic Mg deficits increase the production of free radicals which have been implicated in the development of several chronic age-related disorders. Numerous human diseases have been associated with Mg deficits, including cardiovascular diseases, hypertension and stroke, cardio-metabolic syndrome and type 2 diabetes mellitus, airways constrictive syndromes and asthma, depression, stress-related conditions and psychiatric disorders, Alzheimer's disease (AD) and other dementia syndromes, muscular diseases (muscle pain, chronic fatigue, and fibromyalgia), bone fragility, and cancer. Dietary Mg and/or Mg consumed in drinking water (generally more bioavailable than Mg contained in food) or in alternative Mg supplements should be taken into consideration in the correction of Mg deficits. Maintaining an optimal Mg balance all through life may help in the prevention of oxidative stress and chronic conditions associated with aging. This needs to be demonstrated by future studies.

Magnesium: The recent research and developments

Magnesium is the fourth most abundant mineral in the human body, which facilitates more than 300 enzymatic reactions. Magnesium is essential for nucleic material and protein synthesis, neuromuscular conduction, cardiac contractility, energy metabolism, and immune system function. Gastrointestinal system and kidneys closely regulate magnesium absorption and elimination to maintain adequate storage of magnesium. Magnesium deficiency has been linked to many diseases and poor health outcomes. Magnesium has also been proven to be an effective therapeutic agent in many diseases, such as bronchial asthma, cardiac arrhythmia, and pre-eclampsia.

Magnesium and Hypertension in Old Age

Hypertension is a complex condition in which various actors and mechanisms combine, resulting in cardiovascular and cerebrovascular complications that today represent the most frequent causes of mortality, morbidity, disability, and health expenses worldwide. In recent decades, there has been an exceptional number of experimental, epidemiological, and clinical studies confirming a close relationship between magnesium deficit and high blood pressure. Multiple mechanisms may help to explain the bulk of evidence supporting a protective effect of magnesium against hypertension and its complications. Hypertension increases sharply with advancing age, hence older persons are those most affected by its negative consequences. They are also more frequently at risk of magnesium deficiency by multiple mechanisms, which may, at least in part, explain the higher frequency of hypertension and its long-term complications. The evidence for a favorable effect of magnesium on hypertension risk emphasizes the importance of broadly encouraging the intake of foods such as vegetables, nuts, whole cereals and legumes, optimal dietary sources of magnesium, and avoiding processed foods, which are very poor in magnesium and other fundamental nutrients, in order to prevent hypertension. In some cases, when diet is not enough to maintain an adequate magnesium status, magnesium supplementation may be of benefit and has been shown to be well tolerated.

Perspective: US Adult Magnesium Requirements Need Updating: Impacts of Rising Body Weights and Data-Derived Variance

Adequate magnesium intakes are associated with lower diabetes, hypertension, and cardiovascular disease (CVD) risk but are low in modern diets. Magnesium DRIs, estimated using standard reference body weights (SRBWs) lower than current mean US adult body weights (BWs), need revision. Magnesium DRIs assume variance at 10% CV, whereas balance study data suggests 20-30% CV. Here, estimated average requirements (EARs), the DRI measure estimating average magnesium requirements for healthy adults, were corrected using 2011-2014 mean US adult BWs. Magnesium EARs (in mg magnesium/d) increased 17% for men (330-350 to 386-409) and 25% for women (255-265 to 319-332). RDAs, the DRI measure meant to cover the magnesium needs of 98% of healthy adults, were calculated using BW-corrected EARs given 3 CV levels: 1) 10% (assumed in 1997 DRIs), 2) 20% (model-derived variance from USDA magnesium studies), and 3) 30% (using USDA plus older human magnesium balance data). BW-corrected magnesium RDAs (in mg magnesium/d) rose from 400-420 and 310-320 for men and women, respectively, to 1) 463-491 and 383-398 (16.5% and 23.5% increases), 2) 540-573 and 447-465 (35.5% and 44.5% increases), and 3) 617-654 and 511-531 (55% and 65.5% increases). These recalculations move magnesium intakes estimated to prevent disease into ranges found in traditional diets and to intake levels shown to lower hypertension, diabetes, and CVD risk. In conclusion, mean BW rises over the last ≥20 y and data-driven estimates of CV indicate that reliable US adult magnesium RDAs are ≥60-235 and 70-210 mg magnesium/d higher for men and women, respectively, than the current 1997 RDAs. US adult BMIs are <25 kg/m2 when calculated with SRBWs but >25 with actual mean BWs. Adjustments for rising BW are necessary for magnesium DRIs to remain useful tools for defining magnesium intake adequacy/deficiency.

Reduced Insulin Resistance Partly Mediated the Association of High Dietary Magnesium Intake with Less Metabolic Syndrome in a Large Chinese Population

PURPOSE

High dietary magnesium intake may reduce insulin resistance (IR) and metabolic syndrome (MetS). The aim of the cross-sectional analysis was to evaluate the association between dietary magnesium intake, IR, and MetS using data from China Health and Nutrition Survey.

METHODS

Dietary magnesium intake was defined as daily dietary magnesium intake divided by body weight. Logistic regression analysis was used to calculate the odds ratio (OR) for IR and the prevalence of MetS across the quartile categories of dietary magnesium intake. In addition, we used the macro PROCESS to perform the mediation analyses.

RESULTS

A total of 8120 participants were included in the final analysis. We found a significant negative association between dietary magnesium intake and IR, the multivariable-adjusted OR for HOMA-IR comparing the highest to the lowest quartile of dietary magnesium intake was 0.435 (95% confidence intervals [CI] 0.376 to 0.502). The prevalence of the MetS was 38.6%, 28.9%, 22.5%, and 16.5% for increasing quartiles of dietary magnesium intake (p <0.001). The mediation model analysis displayed that insulin resistance mediated the effect of dietary magnesium on MetS. The direct effect and indirect effect of dietary magnesium on MetS were found significant, and the calculated percentage of mediation by insulin resistance was 19.6%.

CONCLUSION

Our study demonstrated a significant and independent negative relationship among weight-adjusted dietary magnesium intake, HOMA-IR, and MetS in a large Chinese population. IR partly mediated the relationship between dietary magnesium intake and MetS.

No Difference in Magnesium Intake between Obese Women and Healthy Controls

Magnesium is a predominantly intracellular ion and plays an important role in energy metabolism and in the maintenance of energy homeostasis. This study aimed to estimate the dietary intake of magnesium and its association with adiposity parameters in obese women. This cross-sectional study included 125 women, aged between 20 and 50 years, who were divided into two groups: obese group (n = 62) and control group (n = 63). The control group was age-matched. Adiposity parameters determined were weight, body mass index and waist circumference as well as the intake of calories, macronutrients, and magnesium were calculated. The cut-off for obesity was body mass index between 30.0 and 39.9 kg/m² and for control group was between 18.5 and 24.9 kg/m² Food intake was calculated using 3-day food records, and energy consumption as well as the intake of macronutrients and magnesium was calculated using the NutWin software version 1.5. The reference values used were the Acceptable Macronutrient Distribution Range for macronutrients and the Estimated Average Requirement (EAR) for magnesium. The average levels of magnesium found in the diet were lower than those recommended (169.1 ± 64.5 mg Mg/day and 158.5 ± 42.9 mg Mg/day, for obese women and control group, respectively) and the differences between the groups were not statistically different (p > 0.05). The correlation analysis indicated that the association between the dietary intake of magnesium and adiposity was not significant. The results of this study indicate that dietary magnesium does not influence the adiposity parameters in obese women.

The Problematic Use of Dietary Reference Intakes to Assess Magnesium Status and Clinical Importance

Determination of the public health concern about magnesium (Mg) in health and disease has been confounded by the lack of a practical measure of status. This has resulted in a lack of consistency in associating Mg deficiency with specific pathological conditions. Some attempts at associating Mg with a chronic disease have used the Dietary Reference Intakes (DRIs) as a status assessment measure. Use of current DRIs for Mg is problematic because recent evidence suggests that they should be updated and based on body weight. An evidence-based suggested Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) for a 70-kg individual is 175 and 250 mg/day, respectively. However, numerous dietary and physiological factors can affect the need for Mg and thus affect the use of the current or suggested new DRIs to assess Mg status. Calcium intakes above normal requirements can decrease Mg balance and exacerbate signs of Mg deficiency. Mg deficiency apparently occurs often in obesity because of increased need to counteract the inflammatory stress induced by adipose tissue dysfunction. Deficiency in anti-oxidant nutrients such as vitamin E and selenium can exacerbate a response to low dietary Mg indicated by increased oxidative stress which can lead to chronic disease. Dietary modifiers of Mg absorption and excretion affect balance and thus the need for Mg. Factors decreasing Mg balance include low dietary protein and non-fermentable fiber, while factors that can increase balance include fructose and fermentable fiber and fructose-containing oligosaccharides. Use of the DRIs to assess the Mg status of a population or group needs to consider their physiological characteristics and dietary habits and be aware that the DRIs may need updating. The DRIs only can be considered a component of a toolbox that presently includes serum Mg concentration and the daily urinary Mg excretion to assess the Mg status of an individual.

Dietary Magnesium and Chronic Disease

Although official magnesium (Mg) dietary reference intakes are open to question, a significant number of adults likely have intakes that are in the range of 50%-99% of the requirement. This moderate or marginal (subclinical) deficient Mg intake generally is asymptomatic. Animal studies, however, indicate that moderate or subclinical Mg deficiency primes phagocytic cells for the release of proinflammatory cytokines leading to chronic inflammatory and oxidative stress. Human studies have found that dietary Mg is inversely related to serum or plasma C-reactive protein (CRP). Individuals with apparently deficient Mg intakes have an increased likelihood of serum or plasma CRP ≥3.0 mg/L, considered an indicator of chronic inflammatory stress that increases the risk for chronic disease. In addition, elevated serum or plasma CRP in individuals with chronic disease is decreased by Mg supplementation, which suggests that Mg decreases the risk for chronic disease. The importance of dietary Mg intake on the risk for chronic disease through affecting inflammatory and oxidative stress is supported by numerous meta-analyses and systematic reviews that have found dietary Mg is inversely associated with chronic diseases such hypertension, ischemic heart disease, stroke, metabolic syndrome, diabetes, and colorectal cancer.

Magnesium deficiency and increased inflammation: current perspectives

Animal studies have shown that magnesium deficiency induces an inflammatory response that results in leukocyte and macrophage activation, release of inflammatory cytokines and acute-phase proteins, and excessive production of free radicals. Animal and in vitro studies indicate that the primary mechanism through which magnesium deficiency has this effect is through increasing cellular Ca²⁺, which is the signal that results in the priming of cells to give the inflammatory response. Primary pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-1; the messenger cytokine IL-6; cytokine responders E-selectin, intracellular adhesion molecule-1 and vascular cell adhesion molecule-1; and acute-phase reactants C-reactive protein and fibrinogen have been determined to associate magnesium deficiency with chronic low-grade inflammation (inflammatory stress). When magnesium dietary intake, supplementation, and/or serum concentration suggest/s the presence of magnesium deficiency, it often is associated with low-grade inflammation and/or with pathological conditions for which inflammatory stress is considered a risk factor. When magnesium intake, supplementation, and/or serum concentration suggest/s an adequate status, magnesium generally has not been found to significantly affect markers of chronic low-grade inflammation or chronic disease. The consistency of these findings can be modified by other nutritional and metabolic factors that affect inflammatory and oxidative stress. In spite of this, findings to date provide convincing evidence that magnesium deficiency is a significant contributor to chronic low-grade inflammation that is a risk factor for a variety of pathological conditions such as cardiovascular disease, hypertension, and diabetes. Because magnesium deficiency commonly occurs in countries where foods rich in magnesium are not consumed in recommended amounts, magnesium should be considered an element of significant nutritional concern for health and well-being in these countries.

Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis

Because serum magnesium does not reflect intracellular magnesium, the latter making up more than 99% of total body magnesium, most cases of magnesium deficiency are undiagnosed. Furthermore, because of chronic diseases, medications, decreases in food crop magnesium contents, and the availability of refined and processed foods, the vast majority of people in modern societies are at risk for magnesium deficiency. Certain individuals will need to supplement with magnesium in order to prevent suboptimal magnesium deficiency, especially if trying to obtain an optimal magnesium status to prevent chronic disease. Subclinical magnesium deficiency increases the risk of numerous types of cardiovascular disease, costs nations around the world an incalculable amount of healthcare costs and suffering, and should be considered a public health crisis. That an easy, cost-effective strategy exists to prevent and treat subclinical magnesium deficiency should provide an urgent call to action.

Data from Controlled Metabolic Ward Studies Provide Guidance for the Determination of Status Indicators and Dietary Requirements for Magnesium

Determination of whether magnesium (Mg) is a nutrient of public health concern has been hindered by questionable Dietary Recommended Intakes (DRIs) and problematic status indicators that make Mg deficiency assessment formidable. Balance data obtained since 1997 indicate that the EAR and RDA for 70-kg healthy individuals are about 175 and 250 mg/day, respectively, and these DRIs decrease or increase based on body weight. These DRIs are less than those established for the USA and Canada. Urinary excretion data from tightly controlled metabolic unit balance studies indicate that urinary Mg excretion is 40 to 80 mg (1.65 to 3.29 mmol)/day when Mg intakes are <250 mg (10.28 mmol)/day, and 80 to 160 mg (3.29 to 6.58 mmol)/day when intakes are >250 mg (10.28 mmol)/day. However, changing from low to high urinary excretion with an increase in dietary intake occurs within a few days and vice versa. Thus, urinary Mg as a stand-alone status indicator would be most useful for population studies and not useful for individual status assessment. Tightly controlled metabolic unit depletion/repletion experiments indicate that serum Mg concentrations decrease only after a prolonged depletion if an individual has good Mg reserves. These experiments also found that, although individuals had serum Mg concentrations approaching 0.85 mmol/L (2.06 mg/dL), they had physiological changes that respond to Mg supplementation. Thus, metabolic unit findings suggest that individuals with serum Mg concentrations >0.75 mmol/L (1.82 mg/L), or as high as 0.85 mmol/L (2.06 mg/dL), could have a deficit in Mg such that they respond to Mg supplementation, especially if they have a dietary intake history showing <250 mg (10.28 mmol)/day and a urinary excretion of <80 mg (3.29 mmol)/day.

Daily Intake of Magnesium and its Relation to Urinary Excretion in Korean Healthy Adults Consuming Self-Selected Diets

Magnesium (Mg) is an essential nutrient as a structural constituent of bone and regulator of >300 enzymes. However, studies on intake and urinary excretion of Mg are limited. The purpose of this study was to evaluate Mg intake and its relation to 24-h urinary excretion in healthy adults. Anthropometric measurements and dietary intake by the 24-h recall method were conducted in 80 adults aged 21-69 (average 44.3) years. Urine was collected for 24 h on the day following the dietary survey. Dietary assessment and 24-h urine collection were repeated 3 days later. Daily intake and urinary excretion of Mg were analyzed using Can-Pro and ICP-OES, respectively. The statistical analysis was conducted using SAS program. Mg intake of the subjects was 319 ± 129 mg/day for men and 277 ± 94 mg/day for women and the proportion of subjects who did not meet the estimated average requirement was 50 and 67.5 % for men and women, respectively. Urinary Mg excretion was 30.3 % of the daily Mg intake. Urinary Mg excretion was not significantly correlated with the daily Mg intake. Korean adults are not meeting the recommended intake of Mg, but its urinary excretion suggests homeostasis is not compromised.

Dose-response relationship between dietary magnesium intake and cardiovascular mortality: A systematic review and dose-based meta-regression analysis of prospective studies

BACKGROUND

Although epidemiology studies have reported the relationship, including a dose-response relationship, between dietary magnesium intake and risk of cardiovascular disease (CVD), the risk for CVD mortality is inconclusive and the evidence for a dose-response relationship has not been summarized.

OBJECTIVE

We conducted a systematic review and meta-analysis of prospective studies to summarize the evidence regarding the association of dietary magnesium intake with risk of CVD mortality and describe their dose-response relationship.

DESIGN

We identified relevant studies by searching major scientific literature databases and grey literature resources from their inception to August 2015, and reviewed references lists of retrieved articles. We included population-based studies that reported mortality risks, i.e. relative risks (RRs), odds ratios (ORs) or hazard ratios (HRs) of CVD mortality or cause-specific CVD death. Linear dose-response relationships were assessed using random-effects meta-regression. Potential nonlinear associations were evaluated using restricted cubic splines.

RESULTS

Out of 3002 articles, 9 articles from 8 independent studies met the eligibility criteria. These studies comprised 449,748 individuals and 10,313 CVD deaths. Compared with the lowest dietary magnesium consumption group in the population, the risk of CVD mortality was reduced by 16% in women and 8% in men. No significant linear dose-response relationship was found between increment in dietary magnesium intake and CVD mortality across all the studies. After adjusting for age and BMI, the risk of CVD mortality was reduced by 24-25% per 100mg/d increment in dietary magnesium intake in women of all the participants and in all the US participants.

CONCLUSION

Although the combined data confirm the role of dietary magnesium intake in reducing CVD mortality, the dose-response relationship was only found among women and in US population.

Perspective: The Case for an Evidence-Based Reference Interval for Serum Magnesium: The Time Has Come

The 2015 Dietary Guidelines Advisory Committee indicated that magnesium was a shortfall nutrient that was underconsumed relative to the Estimated Average Requirement (EAR) for many Americans. Approximately 50% of Americans consume less than the EAR for magnesium, and some age groups consume substantially less. A growing body of literature from animal, epidemiologic, and clinical studies has demonstrated a varied pathologic role for magnesium deficiency that includes electrolyte, neurologic, musculoskeletal, and inflammatory disorders; osteoporosis; hypertension; cardiovascular diseases; metabolic syndrome; and diabetes. Studies have also demonstrated that magnesium deficiency is associated with several chronic diseases and that a reduced risk of these diseases is observed with higher magnesium intake or supplementation. Subclinical magnesium deficiency can exist despite the presentation of a normal status as defined within the current serum magnesium reference interval of 0.75-0.95 mmol/L. This reference interval was derived from data from NHANES I (1974), which was based on the distribution of serum magnesium in a normal population rather than clinical outcomes. What is needed is an evidenced-based serum magnesium reference interval that reflects optimal health and the current food environment and population. We present herein data from an array of scientific studies to support the perspective that subclinical deficiencies in magnesium exist, that they contribute to several chronic diseases, and that adopting a revised serum magnesium reference interval would improve clinical care and public health.

Micronutrient intake in advanced age: Te Puāwaitanga o Ngā Tapuwae Kia ora Tonu, Life and Living in Advanced Age: A Cohort Study in New Zealand (LiLACS NZ)

A high prevalence of undernutrition has previously been reported in indigenous Māori (49 %) and non-Māori (38 %) octogenarians and may be associated with risk of micronutrient deficiencies. We examined vitamin and mineral intakes and the contributing food sources among 216 Māori and 362 non-Māori participating in Life and Living to Advanced age a Cohort Study in New Zealand, using a repeat 24-h multiple-pass recall. More than half of the Māori and non-Māori participants had intakes below the estimated average requirement from food alone for Ca, Mg and Se. Vitamin B6 (Māori women only), folate (women only), vitamin E (Māori women; all men) and Zn (men only) were low in these ethnic and sex subgroups. Women had intakes of higher nutrient density in folate, vitamin C, Ca, Mg, K, vitamin A (non-Māori) and β-carotene (Māori) compared with men (P<0·05). When controlling for age and physical function, β-carotene, folate, vitamin C, Ca and Mg were no longer significantly different, but vitamins B2, B12, E and D, Fe, Na, Se and Zn became significantly different for Māori between men and women. When controlling for age and physical function, vitamins A and C and Ca were no longer significantly different, but vitamin B2, Fe, Na and Zn became significantly different for non-Māori between men and women. For those who took nutritional supplements, Māori were less likely to be deficient in food alone intake of vitamin A, folate and Mg, whereas non-Maori were less likely to be deficient in intakes of Mg, K and Zn, but more likely to be deficient in vitamin B12 intake. A lack of harmonisation in nutrient recommendations hinders the interpretation of nutrient adequacy; nonetheless, Ca, Mg and Se are key micronutrients of concern. Milk and cheese were important contributions to Ca intake, whereas bread was a key source of Mg and Se. Examination of dietary intake related to biochemical status and health outcomes will establish the utility of these observations.

Moderately Low Magnesium Intake Impairs Growth of Lean Body Mass in Obese-Prone and Obese-Resistant Rats Fed a High-Energy Diet

The physical and biochemical changes resulting from moderately low magnesium (Mg) intake are not fully understood. Obesity and associated co-morbidities affect Mg metabolism and may exacerbate Mg deficiency and physiological effects. Male rats selectively bred for diet-induced obesity (OP, obese-prone) or resistance (OR, obese-resistant) were fed a high-fat, high-energy diet containing moderately low (LMg, 0.116 ± 0.001 g/kg) or normal (NMg, 0.516 ± 0.007 g/kg) Mg for 13 weeks. The growth, body composition, mineral homeostasis, bone development, and glucose metabolism of the rats were examined. OP and OR rats showed differences (p < 0.05) in many physical and biochemical measures regardless of diet. OP and OR rats fed the LMg diet had decreased body weight, lean body mass, decreased femoral size (width, weight, and volume), and serum Mg and potassium concentrations compared to rats fed the NMg diet. The LMg diet increased serum calcium (Ca) concentration in both rat strains with a concomitant decrease in serum parathyroid hormone concentration only in the OR strain. In the femur, Mg concentration was reduced, whereas concentrations of Ca and sodium were increased in both strains fed the LMg diet. Plasma glucose and insulin concentrations in an oral glucose tolerance test were similar in rats fed the LMg or NMg diets. These results show that a moderately low Mg diet impairs the growth of lean body mass and alters femoral geometry and mineral metabolism in OP and OR rats fed a high-energy diet.

Essential Nutrient Interactions: Does Low or Suboptimal Magnesium Status Interact with Vitamin D and/or Calcium Status?

Although much is known about magnesium, its interactions with calcium and vitamin D are less well studied. Magnesium intake is low in populations who consume modern processed-food diets. Low magnesium intake is associated with chronic diseases of global concern [e.g., cardiovascular disease (CVD), type 2 diabetes, metabolic syndrome, and skeletal disorders], as is low vitamin D status. No simple, reliable biomarker for whole-body magnesium status is currently available, which makes clinical assessment and interpretation of human magnesium research difficult. Between 1977 and 2012, US calcium intakes increased at a rate 2-2.5 times that of magnesium intakes, resulting in a dietary calcium to magnesium intake ratio of >3.0. Calcium to magnesium ratios <1.7 and >2.8 can be detrimental, and optimal ratios may be ∼2.0. Background calcium to magnesium ratios can affect studies of either mineral alone. For example, US studies (background Ca:Mg >3.0) showed benefits of high dietary or supplemental magnesium for CVD, whereas similar Chinese studies (background Ca:Mg <1.7) showed increased risks of CVD. Oral vitamin D is widely recommended in US age-sex groups with low dietary magnesium. Magnesium is a cofactor for vitamin D biosynthesis, transport, and activation; and vitamin D and magnesium studies both showed associations with several of the same chronic diseases. Research on possible magnesium and vitamin D interactions in these human diseases is currently rare. Increasing calcium to magnesium intake ratios, coupled with calcium and vitamin D supplementation coincident with suboptimal magnesium intakes, may have unknown health implications. Interactions of low magnesium status with calcium and vitamin D, especially during supplementation, require further study.

Towards bio monitoring of toxic (lead) and essential elements in whole blood from 1- to 72-month old children: a cross-sectional study

OBJECTIVES

Minerals such as zinc, copper, selenium, calcium, and magnesium are essential for normal human development and functioning of the body. They have been found to play important roles in immuno-physiologic functions. The study is to evaluate the distribution and correlation of nonessential (lead) and essential elements in whole blood from 1- to 72-month old children.

METHODS

The cross-sectional study was performed in 1551 children. Six element concentrations, including copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), iron (Fe) and lead (Pb) in the blood were determined by atomic absorption spectrometry. Distributions and correlations of trace elements in different age groups were analyzed and compared. A Pearson correlation controlled for age and gender was used to assess the relationship of non essential (lead) and essential elements.

RESULTS

Levels of copper and magnesium were 18.09 ± 4.42 µmol/L and 1.42 ± 0.12 mmol/L, respectively. 6.04% of all children showed copper levels below the normal threshold, the levels of Magnesium were stable in different age groups. Though the overall mean blood zinc and iron concentrations (61.19 ± 11.30 µmol/L and 8.24 ± 0.59 mmol/L, respectively) gradually increased with age and the overall deficiency levels (24.1% and 36.0%, respectively) decreased with age, zinc and iron deficiencies were still very stable. Controlling for gender and age, significant positive correlations were found when comparing copper to zinc, calcium, magnesium, and iron ((r = 0.333, 0.241, 0.417, 0.314 ,p < 0.01); zinc to magnesium and iron (r = 0.440, 0.497p < 0.01); and magnesium to Calcium and iron (r = 0.349, 0.645, p < 0.01). The overall mean blood lead levels (41.16 ± 16.10) were relatively unstable among different age groups. The prevalence of lead intoxication in all children was 1.3% .Calcium levels decreased gradually with age, with an overall concentration of 1.78 ± 0.13 mmol/L.

CONCLUSION

Significant negative correlations were also noted between Pb and Zn, Fe (r = -0.179, -0.124.p < 0.01) .The importance of calcium deficiency and supplementation is well realized, but the severity of iron and zinc deficiency is not well recorded. The degree of lead intoxication in all the children studied was low; The established reference intervals for Cu, Zn, Ca and Mg provide an important guidance for the reasonable supplementation of essential elements during different age groups.

Lower serum magnesium concentration is associated with diabetes, insulin resistance, and obesity in South Asian and white Canadian women but not men

Background

A large proportion of adults in North America are not meeting recommended intakes for magnesium (Mg). Women and people of South Asian race may be at higher risk for Mg deficiency because of lower Mg intakes relative to requirements and increased susceptibility to diabetes, respectively.

Objective

This study compared serum Mg concentrations in South Asian (n=276) and white (n=315) Canadian women and men aged 20–79 years living in Canada's Capital Region and examined the relationship with diabetes, glucose control, insulin resistance, and body mass index.

Results

Serum Mg concentration was lower in women of both races and South Asians of both genders. Racial differences in serum Mg were not significant after controlling for use of diabetes medication. A substantial proportion of South Asian (18%) and white (9%) women had serum Mg <0.75 mmol/L indicating hypomagnesemia. Use of diabetes medication and indicators of poorer glucose control, insulin resistance, and obesity were associated with lower serum Mg in women, but not in men.

Conclusions

These results suggest that the higher incidence of diabetes in South Asians increases their risk for Mg deficiency and that health conditions that increase Mg requirements have a greater effect on Mg status in women than men.

Effects of magnesium depletion on inflammation in chronic disease

PURPOSE OF REVIEW

To update findings supporting the opinion that commonly occurring subclinical magnesium deficiency induced by a low dietary intake is a predisposing factor for chronic inflammatory stress that contributes to the incidence of chronic diseases such as cardiovascular disease and diabetes.

RECENT FINDINGS

Both deficient magnesium intakes (<250 mg/day) and serum magnesium concentrations (≤ 0.75 mmol/l) have been associated with elevated serum C-reactive protein concentration, a widely used indicator of inflammation. Achieving magnesium intakes or serum magnesium concentrations that indicate an adequate magnesium status generally attenuates elevated serum C-reactive protein to concentrations that are not indicative of chronic low-grade inflammation. Individuals that are obese or have chronic diseases for which low-grade inflammation is a risk factor are commonly found to be magnesium-deficient.

SUMMARY

Subclinical magnesium deficiency caused by low dietary intake often occurring in the population is a predisposing factor for chronic inflammatory stress that is conducive for chronic disease. Magnesium deficiency should be considered a nutrient of significant concern for health and well-being.

IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty

The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects.

Dietary magnesium intake improves insulin resistance among non-diabetic individuals with metabolic syndrome participating in a dietary trial

Many cross-sectional studies show an inverse association between dietary magnesium and insulin resistance, but few longitudinal studies examine the ability to meet the Recommended Dietary Allowance (RDA) for magnesium intake through food and its effect on insulin resistance among participants with metabolic syndrome (MetS). The dietary intervention study examined this question in 234 individuals with MetS. Magnesium intake was assessed using 24-h dietary recalls at baseline, 6, and 12 months. Fasting glucose and insulin levels were collected at each time point; and insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). The relation between magnesium intake and HOMA-IR was assessed using linear mixed models adjusted for covariates. Baseline magnesium intake was 287 ± 93 mg/day (mean ± standard deviation), and HOMA-IR, fasting glucose and fasting insulin were 3.7 ± 3.5, 99 ± 13 mg/dL, and 15 ± 13 μU/mL, respectively. At baseline, 6-, and 12-months, 23.5%, 30.4%, and 27.7% met the RDA for magnesium. After multivariate adjustment, magnesium intake was inversely associated with metabolic biomarkers of insulin resistance (P < 0.01). Further, the likelihood of elevated HOMA-IR (>3.6) over time was 71% lower [odds ratio (OR): 0.29; 95% confidence interval (CI): 0.12, 0.72] in participants in the highest quartile of magnesium intake than those in the lowest quartile. For individuals meeting the RDA for magnesium, the multivariate-adjusted OR for high HOMA-IR over time was 0.37 (95% CI: 0.18, 0.77). These findings indicate that dietary magnesium intake is inadequate among non-diabetic individuals with MetS and suggest that increasing dietary magnesium to meet the RDA has a protective effect on insulin resistance.

Modeling and simulation of the effect of proton pump inhibitors on magnesium homeostasis. 1. Oral absorption of magnesium

Prolonged use of proton pump inhibitors has reportedly caused rare clinically symptomatic hypomagnesemia. A review of the literature suggests PPI drugs may impair intestinal magnesium absorption. With the goal of preventing PPI-induced hypomagnesemia, an oral absorption-centric model was developed by referencing literature data. Our modeling with human data reveals that magnesium absorption is substantial in the distal intestine. We then perform simulations by referring to the reported reduction in mid to distal intestinal pH caused by one week of oral esomeprazole, and to reported reduction of the divalent cation-sensitive current when the carboxyl side chains of glutamic and aspartic residues in the binding channels of TRPM6/TRPM7 were neutralized. Our simulations reveal that short-term PPI therapy may cause a very small reduction (5%) in the serum magnesium level, which is qualitatively consistent with the reported 1% reduction in magnesium absorption following 1 week of omeprazole in humans. Simulations provide insight into the benefit of frequent but small dose of magnesium supplementation in maintaining the serum magnesium level when magnesium deficiency occurs.

Suboptimal magnesium status in the United States: are the health consequences underestimated?

In comparison with calcium, magnesium is an "orphan nutrient" that has been studied considerably less heavily. Low magnesium intakes and blood levels have been associated with type 2 diabetes, metabolic syndrome, elevated C-reactive protein, hypertension, atherosclerotic vascular disease, sudden cardiac death, osteoporosis, migraine headache, asthma, and colon cancer. Almost half (48%) of the US population consumed less than the required amount of magnesium from food in 2005-2006, and the figure was down from 56% in 2001-2002. Surveys conducted over 30 years indicate rising calcium-to-magnesium food-intake ratios among adults and the elderly in the United States, excluding intake from supplements, which favor calcium over magnesium. The prevalence and incidence of type 2 diabetes in the United States increased sharply between 1994 and 2001 as the ratio of calcium-to-magnesium intake from food rose from <3.0 to >3.0. Dietary Reference Intakes determined by balance studies may be misleading if subjects have chronic latent magnesium deficiency but are assumed to be healthy. Cellular magnesium deficit, perhaps involving TRPM6/7 channels, elicits calcium-activated inflammatory cascades independent of injury or pathogens. Refining the magnesium requirements and understanding how low magnesium status and rising calcium-to-magnesium ratios influence the incidence of type 2 diabetes, metabolic syndrome, osteoporosis, and other inflammation-related disorders are research priorities.

Magnesium content in daily food portions and the influence of supplementation

Magnesium is one of the most important cations for an organism. The aim of our study is to evaluate whether the use of a magnesium formulation as a diet supplement or medical treatment is necessary. The 24-hour recall method was used to obtain information regarding the daily magnesium consumption of 949 people. The results were compared with the Estimated Average Requirement (EAR) and Recommended Daily Allowance (RDA) values. The average daily requirement for magnesium was exceeded by 292 (183 women and 109 men) of the 949 respondents. This research confirmed excessive magnesium intake by both men and women that exceeded both the EAR and the RDA. Uncontrolled, excessive dietary supplementation or medical treatment with magnesium by this group may constitute a health threat.

Blood lead level and its relationship to certain essential elements in the children aged 0 to 14 years from Beijing, China

OBJECTIVE

To investigate blood lead level and its relationship to copper, zinc, calcium, magnesium and iron in the children aged 0 to 14 years old from Beijing, China.

METHODS

We classified 3181 children into one of the four groups: Group A (n=783, <1 year old); Group B (n=1538, 1-3 years old); Group C (n=443, 3-7 years old); and, Group D (n=417, 7-14 years old). All these metal elements were determined by atomic absorption spectrometry.

RESULTS

The blood lead level was 0.207±0.105 μmol/L. There was a significant gender difference for zinc (P<0.05) in Group C, and there was also a significant gender difference for copper (P<0.05) and lead (P<0.05) in Group D. Controlling for gender and age, we observed that there was a negative correlation of lead with zinc (r=-0.052, P<0.01), magnesium (r=-0.042, P<0.05) and iron (r=-0.031, P<0.05), respectively. Furthermore, in the children aged 1-7 years old, we also found there was a negative linear correlation of lead with zinc, magnesium and iron, respectively (P<0.01).

CONCLUSION

Blood lead level in children from Beijing was markedly decreased. And deficiency of zinc, magnesium and iron is related to the elevated blood lead level in the children aged 1-7 years.

Reported zinc, but not copper, intakes influence whole-body bone density, mineral content and T score responses to zinc and copper supplementation in healthy postmenopausal women

A supplementation trial starting with 224 postmenopausal women provided with adequate vitamin D and Ca was conducted to determine whether increased Cu and Zn intakes would reduce the risk for bone loss. Healthy women aged 51–80 years were recruited for a double-blind, placebo-controlled study. Women with similar femoral neck T scores and BMI were randomly assigned to two groups of 112 each that were supplemented daily for 2 years with 600 mg Ca plus maize starch placebo or 600 mg Ca plus 2 mg Cu and 12 mg Zn. Whole-body bone mineral contents, densities and T scores were determined biannually by dual-energy X-ray absorptiometry, and 5 d food diaries were obtained annually. Repeated-measures ANCOVA showed that bone mineral contents, densities and T scores decreased from baseline values to year 2. A priori contrasts between baseline and year 2 indicated that the greatest decreases occurred with Cu and Zn supplementation. Based on 5 d food diaries, the negative effect was caused by Zn and mainly occurred with Zn intakes ≥ 8·0 mg/d. With Zn intakes < 8·0 mg/d, Zn supplementation apparently prevented a significant decrease in whole-body bone densities and T scores. Food diaries also indicated that Mg intakes < 237 mg/d, Cu intakes < 0·9 mg/d and Zn intakes < 8·0 mg/d are associated with poorer bone health. The findings indicate that Zn supplementation may be beneficial to bone health in postmenopausal women with usual Zn intakes < 8·0 mg/d but not in women consuming adequate amounts of Zn.

Aspectos atuais da relação entre exercício físico, estresse oxidativo e magnésio

Este trabalho visa a contribuir com informações atualizadas sobre a relação entre exercício, estresse oxidativo e magnésio. São escassos os trabalhos que discutem a produção de radicais livres nesse contexto. A deficiência de magnésio altera a fluidez das membranas celulares e mitocondriais e promove perturbações na homeostase do cálcio e na atividade das defesas antioxidantes. No exercício, a falta de magnésio nos tecidos musculares os torna mais suscetíveis à infiltração de macrófagos e neutrófilos e ao rompimento do sarcolema, dificultando o processo de regeneração e podendo ocasionar queda no desempenho físico. Conclui-se que o papel metabólico da deficiência de magnésio no estresse oxidativo induzido pelo exercício deve ser mais pesquisado, focalizando os seus efeitos na musculatura esquelética em indivíduos que praticam exercício regular e na deficiência marginal de magnésio.